Styrene derivatives having a fluorinated organic group substituted at the para position are known in the art, for example, benzyl ethers of the general formula: ##STR2## wherein R.sup.1 and R.sup.2 are polyfluoroalkyl groups as disclosed in Japanese Patent Application Kokai No. 293943/1986. Introduction of such a polyfluoroalkyl group into the substituent moiety of styrene can impart water repellency, oil repellency and chemical resistance attributable to fluorine to a homopolymer of the styrene or a copolymer of the styrene with another polymerizable monomer at the sacrifice of flexibility. It is thus desired to overcome the drawback that the resulting polymers are brittle.